College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

تمرين 104

A railroad flatbed car is set up for a physics demonstration. It is set to roll horizontally on its straight rails at a constant speed of 12.0 m/s. On it is rigged a small launcher capable of launching a small lead ball vertically upward, relative to the bed of the car, at a speed of 25.0 m/s. (a) Compare [by making two sketches] the description of the motion from the point of view of two different observers: one riding on the car and one at rest on the ground next to the tracks. (b) How long does it take the ball to return to its launch location (c) Compare the ball's velocity at the top of its motion from the viewpoint of each of the two observers and explain any differences. (d) What is the launch angle (relative to the ground) and speed of the ball according to the ground observer (e) How far down the rails has the car moved when the ball lands back at the launcher Compare this distance to how far the ball has moved relative to the car.